The present disclosure relates generally to information handling systems, and more particularly to dynamic power allocation for information handling systems receiving power using power over Ethernet technology.
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option is an information handling system (IHS). An IHS generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes. Because technology and information handling needs and requirements may vary between different applications, IHSs may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in IHSs allow for IHSs to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, IHSs may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Some IHSs use Power over Ethernet (PoE) technology to send power and data to other IHSs and/or receive power and data from other IHSs. PoE technology provides for the transmission of power, along with the data, safely over Ethernet cabling. The original Institute of Electrical and Electronics Engineers (IEEE) 802.3af standards provide up to 15.4 watts (W) of DC power (minimum 44 volts (V) direct current (DC) and 350 milliamps (mA)), while the updated IEEE 802.3at standards (also known as PoE+) provides up to 25.5 W. The IEEE 802.3af and IEEE 802.3at standards provide for the classification of powered devices (PDs) based on a predefined control protocol or hardware classification, and the power sourcing equipment (PSE) device statically assigns the power level of the power that will be provided to the PD based on the amount designated in the standards for the PD's classification. There are currently 5 classifications: Class 0, the default classification, provides for devices that draw a current of 0-4 mA and a power range of 0.44-12.94 W. Class 1 provides for devices that draw a current of 9-12 mA and a power range of 0.44-3.84 W. Class 2 provides for devices that draw a current of 17-20 mA and a power range of 3.84-6.49 W. Class 3 provides for devices that draw a current of 26-30 mA and a power range of 6.49-12.95 W. Class 4, used by 802.3 at devices, provides for devices that draw a current of 36-44 mA and a power range of 12.95-25.5 W.
The static assignment by the PSE device of the power level that will be provided to a PD based on the classification discussed above raises a number of issues. Such static assignments result in the PSE device statically allocating the maximum amount of power needed by a PD of that class when operating (e.g., a PD classified as a class 3 device results in the PSE statically allocating 12.95 W to that PD even if that PD actually draws a maximum of only 8 W power.) Thus, current PoE power systems are inefficient in their allocation of power due to their static assignment of power to PDs based on a classification that can result in the PSE assigning more power to a PD than is necessary
Accordingly, it would be desirable to provide an improved PoE power allocation system.